1. Field of the Invention
The present invention relates to chairs in general, and more particularly to recliner chairs and lift chairs, and more particularly still to recliner and lift chairs in which the angle and position of the back frame is adjustable using a reversible electronic actuator independent of any movement or positioning of the seat frame and footrest, and more particularly still to reclining and lift chairs in which the chair can be positioned in both a zero gravity and Trendelenburg position.
2. Preliminary Discussion
Recliner chairs and lift chairs have been on the market for years, with the utility of recliners being primarily for leisure use in living rooms and family rooms, while lift chairs are used primarily by the handicapped, elderly, or disabled to assist them in moving from a reclined or sitting position into a standing position. While a substantial number of today's recliners are still manually operated, a growing number of recliners, and almost all lift chairs, utilize one or more actuator mechanisms to move the footrest, back frame, and seat frame into various lift and/or recline positions with respect to each other. In one known chair type, independent movement of the footrest and backrest is accomplished through the use of separate actuators, while other chairs utilize a single interconnected actuator to cause the footrest and backrest to move together or simultaneously. In known recliner chairs in which the back frame is independently movable, the back frame actuator connects between the back frame and either the chair frame or lift frame. Unfortunately, the range of movement in which the back frame can be pivoted or moved using the back frame actuator without one or more parts of the actuator mechanism being impeded or obstructed by another part or component of the chair, such as the chair frame, lift frame actuator, or seat frame, is rather limited, and in some chairs also depends upon the particular lift or recline position the chair is in. In other words, despite the use of a separate chair back actuator, the position adjustability of the back frame is still limited.
In addition to the usual television watching and other relaxing positions, a few known chairs can also be moved or pivoted into certain special positions. One such position is the so-called Trendelenburg position, wherein the occupant's legs are situated so that they are higher in relation to the ground than the heart. This position is useful particularly for those having certain circulatory, kidney, or other ailments, since in such position gravity assists the flow of blood from the legs back to the heart. Another special position is the so-called “zero gravity” or 90/90 position. To achieve such position, the chair is adjusted so that the occupant's head and torso are at a slight upward angle, the legs up to the knee are bent at a similar opposite upward angle, and the knees are bent so that the lower area of the legs is angled similarly to the torso. The zero-gravity position approximates the position or posture that astronauts assume when sleeping in a weightless environment. The primary benefit of such position is reduced pressure on the spine, which often relieves back pain at least to some extent. Other benefits include reduced heart stress, relief of tension in the body, and improved circulation. So far as the inventors are aware, no prior art motor actuated reclining lift chairs or recliners can achieve both the Trendelenburg and zero-gravity positions as well as independent movement of the back frame relative to the seat frame and footrest throughout its full range of motion regardless of the lift or recline position the chair is in.
It has now been discovered that by securing the actuator mechanism for independently adjusting the position or angle of the back frame with respect to the seat frame between the back frame or linkages connected to the back frame on one end and the seat frame or linkages connected to, or moving along with or following the movement of the seat frame on the other end, such that the back frame actuator can follow or move along with the seat as the position of the seat is adjusted using another actuator, the back frame can be moved to any position the actuator mechanism is capable of providing without being impeded by or coming into contact with any other parts of the chair, in any lift and/or recline position the chair is capable of achieving. Thus, in one embodiment, as the footrest pivots upwardly, the seat and back frames as a result of the particular linkage mechanism selected will at the same time move rearwardly until the footrest is in a substantially horizontal position. Then, if one tries to move the footrest beyond such substantially horizontal position, the footrest as well as the seat and back frames will both move together in a generally upward direction. At the same time, or at a different time, the back frame can be moved independently of both the footrest and seat frame using its own actuator. In another embodiment, the footrest can also be operated and its position adjusted independent of both the seat frame and back frame using a third actuator.
Where such a back frame actuator and linkage mechanism arrangement is provided on a combination recliner and lift chair, the actuator for the footrest and seat frame will be moved to a closed position and then continue beyond such position until the frame of the chair is lifted upwardly and tilted forwardly by the lift assembly. By arranging the actuators in such a manner, the chair can provide multiple positioning of the occupant or user ranging from the Trendelenburg position to various recline and lift positions. Such arrangement also enables the footrest, back frame, and seat frame to move together if desired, while moving the footrest and seat together, with the seat moving rearwardly, allows the seat to be articulated up at an angle which is comfortable and puts the occupant in a so-called “zero gravity” or back relief position, which provides complete support for the occupant and takes pressure off the spine. Where the footrest is not also independently adjustable, a size-adjustable stop may be used to alter slightly the final angle of the footrest in relation to the seat frame to customize the zero gravity position of the chair.
3. Description of Related Art
The related art evidences multiple chairs consisting of known and expected structural configurations designed to move between a reclined position, a sitting position, and a lift position wherein the occupant is enabled more easily to assume a standing or upright position, as well as a wide range of alternative designs that have been developed to fulfill countless specific objectives and requirements. The following patent documents are illustrative of the present state of this field.
U.S. Pat. No. 3,016,264 issued to A. L. Hughes on Jan. 9, 1962, entitled “Motor-Operated Reclining Chair”, discloses a recliner wherein the backrest is pivotally mounted to the side arms of the chair, and is movable by a drive mechanism. However, the back rest is prevented from freely pivoting by a pair of parallel spaced-apart linkages, and therefore suffers from the disadvantage of having a limited range of motion.
U.S. Pat. No. 3,743,348 issued to C. J. Sloan on Jul. 3, 1973, entitled “Reclining Chair and Mechanism Therefore”, discloses a recliner assembly wherein in one embodiment, dual motors are provided, with motor 120 being used to pivot the back frame, while motor 126 is used to deploy the footrest. When back frame motor 120 is actuated, however, due to the nature of the linkage arrangement movement of the back frame causes the rear end of the seat frame to drop and then move upwardly, thus limiting the number of reclining positions.
U.S. Pat. No. 4,007,960 issued to E. J. Gaffney et al. on Feb. 15, 1977, entitled “Reclining Elevator Chair”, discloses a lift-recliner chair which is movable to a substantially fully reclined position; however, the back frame is movable with respect to the seat only when the entire chair is being moved to a reclined position, rather than moved independently of the position of the seat frame and footrest.
U.S. Pat. No. 4,365,836 issued to W. R. Jackson et al. on Dec. 28, 1982, entitled “Motorized Reclining Chair”, discloses a recliner chair having a single motor or actuator. While the linkage system for such chair enables it to be moved to a conventional television viewing position and a resting position, there is no means for changing the position of the backrest independently of the position of the seat frame or footrest.
U.S. Pat. No. 4,386,803 issued to C. W. Gilderbloom on Jun. 7, 1983, entitled “Motorized Reclining Chair”, discloses a recliner wherein the chair back, seat, and legrest are said to be independently adjustable. However, while such chair appears to be capable of attaining a wider than usual range of reclining positions, the seat is separately connected to the frame on roller guides, and is moved on the guides in response to abutting contact with the back as it is moved using the back motor. In addition, the footrest or ottoman does not retract to a conventional closed recliner position.
U.S. Pat. No. 4,852,939 issued to B. J. Krauska on Aug. 1, 1989, entitled “Device for Converting a Recliner Chair to a Recliner-Lift Chair”, discloses a chair base that when connected to a conventional recliner converts it into a power actuated recliner and lift chair. The back frame, however, is not independently movable, and therefore the number of reclining positions that can be achieved with such chair is comparatively limited.
U.S. Pat. No. 5,013,084 issued to T. J. May on May 7, 1991, entitled “Mechanism for High-Leg Reclining Apparatus”, discloses a dual legrest type recliner chair capable of attaining an upright, TV, and fully reclined position. The linkage of the chair back frame to the seat frame does not allow for independent movement of the chair back, however.
U.S. Pat. No. 5,165,753 issued to E. D. Henderson on Nov. 24, 1992, entitled “Elevator Chair Apparatus” discloses a lift chair wherein the sub-frame pivots on a base portion having a rearwardly inclined upper surface. In a lift position, the sub-frame pivots on the front edge of the inclined surface via an actuator.
U.S. Pat. No. 5,520,439 issued to E. D. Blount on May 28, 1996 entitled “Fully Reclinable Elevator Lift Chair”, discloses a lift-recliner chair that is an improvement on the Henderson '753 chair in that it can also be moved to a fully reclined position, while the Henderson chair cannot. The actuator in Blount is connected between the base and a pivotable transverse bar on which the back is supported by brackets, so that when the motor ram is moved away from the motor, eventually the bar pivots to cause the back to recline. See also commonly owned continuation-in-part U.S. Pat. No. 5,806,920 entitled “Fully Reclinable Elevator Lift Chair with Ottoman” wherein an elevatable footrest is also provided. None of such arrangements appears to allow for completely independent adjustment of the back frame, however.
U.S. Pat. No. 5,265,935 issued to G. Geisler et al. on Nov. 30, 1993, entitled “Stand-Assist Recliner Chair”, discloses a lift-recliner chair in which the actuator is secured between two separate crank arms under the chair seat. The linkage mechanism used, however, does not appear to provide the same maneuverability of the back section as is possible with the present inventors' arrangement.
U.S. Pat. No. 5,312,153 issued to J. Lin on May 17, 1994, entitled “Recline Lift Wall Hugger Chair”, discloses an arrangement for enabling a chair to pivot forwardly, or away, from a wall when it is to be moved into a reclining position. In the embodiment shown in FIGS. 12-14, the backrest is tiltable relative to the seat using a crank arm connection arrangement between the backrest and seat. However, the seat still must move forwardly for the back to achieve a fully reclined position, and there is no means for independently pivoting the backrest with respect to the seat portion.
U.S. Pat. No. 5,354,116 issued to T. J. May et al. on Oct. 11, 1994, entitled “Reclining Chair with Articulating Linkage for Padded Intermediate Ottoman”, discloses a recliner having a linkage mechanism connecting the legrest, seat, and backrest. The linkage system does not provided for independent movement of the backrest, however.
U.S. Pat. No. 5,498,055 issued to P. R. Goldman on Mar. 12, 1996, entitled “Recliner Apparatus and Method”, discloses a recliner wherein the user's feet are elevated above his or her heart in a fully reclined position. As shown in FIG. 2, the entire chair can pivot about an axis (21) in relation to the chair frame (13), while the seat and back as well as the seat and footrest are also independently pivotable with respect to one another, so that numerous reclined positions are possible, one of which is to have the footrest raised upwardly so that the user's feet are above his or her heart. A means for automatically moving the footrest when the backrest is rotated is also provided. While the Goldman recliner therefore can be moved into a Trendelenburg position, this is accomplished in a completely unique manner unlike the present invention and without the use of motorized actuators, and it is unclear whether a bed-like position can be reached.
U.S. Pat. No. 5,582,457 issued to K. J. Komorowski et al. on Dec. 10, 1996, entitled “Dual Legrest Assembly”, discloses a linkage assembly for a legrest wherein coordinated movement of first and second legrest panels, i.e., a dual legrest, is provided. A separate linkage means for tilting the backrest is also shown, but the back frame is not movable via a power actuator means.
U.S. Pat. No. 5,651,580 issued to L. P. LaPointe et al. on Jul. 29, 1997, entitled “Linear Actuation Drive Mechanism for Power-Assisted Chairs and Base Therefor”, discloses a lift-recliner chair that utilizes a single linear action drive mechanism to selectively actuate the reclining linkage assembly, footrest linkage assembly, and the lift and tilt assembly. Such chair, which is the subject of several related patents, does not appear to include a motor actuated system for independently adjusting the position of the backrest.
U.S. Pat. No. 6,000,758 issued to W. E. Schaffner et al. on Dec. 14, 1999, entitled “Reclining Lift Chair”, discloses a chair having a novel linkage mechanism system for lifting and reclining in which when a bell crank is pivoted in a clockwise direction by an actuator, the chair back is caused to recline, and in addition having an environmental control system. There does not appear to be a means for independently adjusting the position of the chair back with respect to the chair seat frame in any of the disclosed embodiments, however, so that the range of positions in which the chair can be reclined is limited in comparison to the present invention.
U.S. Pat. No. 6,022,076 issued to I. Samson on Feb. 8, 2000, entitled “Reclinable Seating”, discloses a recliner chair in which the center of gravity of the reclining unit remains in a horizontal plane as it moves between an upright and reclined position, thereby increasing the stability of such chair in these positions. While the Samson recliner appears to possibly be movable to a zero-gravity position, such chair does not disclose any of the unique features of the present invention.
U.S. Pat. No. 6,135,559 issued to J. R. Kowalski on Oct. 24, 2000, entitled “Seat Back Reclining Mechanism Adaptable to Chairs with Stationary or Movable Seats”, discloses a recliner that includes a linkage mechanism for pivoting the seat back independent of and without regard to the position of the seat. However, movement of the back is initiated by applying a manual force against the chair back and opposing the force of a coil spring, rather than utilizing a power actuator to move the seat, and the number of reclined positions is limited in comparison to the present invention.
U.S. Pat. No. 6,142,558 issued to T. J. May on Nov. 7, 2000, entitled “Recliner with Primary and Secondary Ottomans”, discloses a “low leg” recliner chair having a unitary linkage arrangement for the chair legrest, seat, and back. The May chair is not motor actuated, however, and the backrest appears to pivot in unison with the seat, rather than completely independent of the seat movements as in the present invention.
U.S. Pat. No. 6,213,554 issued to Y. Marcoux et al. on Apr. 10, 2001, entitled “Lift Chair”, discloses a lift chair mechanism for a lift chair having a chair frame that can be reclined independently of the lift mechanism and base frame, as well as providing for a rocking motion. The chair back cannot be reclined independent of the seat frame, however.
U.S. Pat. No. 6,840,575 issued D. Hesse on Jan. 11, 2005, entitled “Seat-Recliner Fitting That Can Be Adjusted by a Motor”, discloses a fitting for adjusting the inclination of a seat back and a footrest of a recliner using separate actuators. The specification indicates that the seat is moved forward at the same time the back is moved. In addition, the linkage mechanism on which the seat is pivoted is unlike that of the present lift-recliner chair, and use of an adjustable size spacer for microadjustment of the angle of the footrest in a fully reclined position is not disclosed.
German Gebrauchmuster Patent Application DE 9420149.8 filed by W. Hoormann et al. on Dec. 16, 1994, discloses in FIGS. 1 and 2 a recliner having a pair of actuators or motors, one of which is connected to the backrest. The backrest motor appears to be connected to a stationary position on the chair frame rather than the seat, and therefore would not provide the same advantages available in the present invention.
U.K. Patent Application 2,030,854 published on Apr. 16, 1980, entitled “Reclining Chair”, discloses a recliner wherein the seat and back are pivotally connected to the base as well as to each other. When the back pivots, the seat also must pivot, so that there does not appear to be a means for pivoting the seat independently of the back.
U.K. Patent Application No. 2,407,493 published on Apr. 5, 2005 entitled “Powered Lift Reclining Chair”, discloses a lift-recliner chair having an actuator for pivoting the back portion with respect to the seat portion, as well as the seat portion with respect to the base portion. The actuators are substantially enclosed within the base portion of the chair at all positions of the chair, which arrangement reduces the risk of entrapment and injury during movement of the chair (as shown in FIGS. 2 and 3). It is indicated that the actuator for moving the back portion is “fixed” relative to the seat portion. As shown in FIG. 2, however, actuator (66) is mounted to base frame cross member (26) on one end and the actuator arm (67) is mounted to cross member (60), not the seat frame.
While the aforementioned prior art devices fulfill their respective, particular objectives and requirements, they do not disclose a lift or recliner chair having the particular capabilities and advantages of the present invention. The chair according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides a lift and recliner chair having an independently operating back and in one embodiment a movement rearwardly and upwardly of the seat to a substantially reclining position as the footrest is activated, that is capable of easily achieving a wider range of reclining positions, including both a Trendelenburg and zero-gravity position.